Simulate pendulum clock

ABSTRACT

A pendulum clock powered by direct current wherein a pendulum is functionally separated from a timekeeping movement for driving the hands of the clock. A unique separate electromagnetic motor for driving the pendulum is located below the timekeeping movement.

limited States Patent 1 Petr-ides 1 1 Oct. 2, 1973 1 SlMUlLATE PENDULUMCLOCK {75] Inventor: Christie Petr-ides, Medway, Mass,

[73] Assignee: General Electric Company,

Bridgeport, Conn.

122] Filed: Dec. 23, 1971 211 App1.No.:2ll,578

[52] US. Cl 58/29, 58/33, 58/129 [51] Int. Cl. G041) 47/04 [58] Field01' Search 58/23 V, 23 D, 29,

[56] References Cited UNlTED STATES PATENTS 1,743,231 l/1930 Packard58/29 3,424,960 H1969 Ross 308,731 12/1884 Bailey 418,125 12/1889Hamblet 1,831,260 11/1931 Poole.....' 58/29 FOREIGN PATENTS ORAPPLlCATlONS 323,001 12/1929 Great Britain 58/29 596,216 12/1947 GreatBritain 58/129 Primary Examiner-Richard B. Wilkinson AssistantExaminerU. Weldon AlmrneyLawrence R. Kempton et a1.

[57] ABSTRACT A pendulum clock powered by direct current wherein apendulum is functionally separated from a timekeeping movement fordriving the hands of the clock. A unique separate electromagnetic motorfor driving the pendulum is located below the timekeeping movement.

5 Claims, 6 Drawing Figures PATENTEDBBT 2 3,762,154

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SIMULA'IIE PENIDIJLUM CLOCK BACKGROUND OF THE INVENTION This inventionrelates to a pendulum clock powered by direct current, and moreparticularly, to a unique separate electromagnetic mechanism for drivinga pendulum of a clock.

Most contemporary battery-operated clocks include a low power electronictimekeeping movement which is adequate for driving the hands of a clock,and while such a clock movement is entirely satisfactory for thefunctional purpose of timekeeping, the timekeeping motor or movement isnot capable of driving a relatively large ornamental pendulum.

Oldfashioned swinging pendulum clocks wherein a pendulum is structurallyintegrated into the clock mechanism to perform a timekeeping functionare still considered by the clock industry to be asthetically appealingto a significant number of people. Accordingly, some contemporary priorart pendulum clocks have the appearance and apparent external operationof an oldfashioned swinging pendulum clock, and yet the pendulum doesnot serve a timekeeping function. Most of these contemporary pendulumclocks have included a synchronous electric motor which utilizes theordinary house wiring as a source of electric power, and all of theseprior art simulated pendulum clocks have used the same motor that isused for timekeeping to provide the power to drive the pendulum. Forexample, in a prior US. Pat. No. 2,995,005 to Boyles, dated Aug. 8, 1961and assigned to the same assignee as the present invention, there isdisclosed a simulated swinging pendulum clock in which an electric motor114 is provided for driving the hands of the clock and also the pendulumof the clock. Such a prior art simulated pendulum clock mechanismrequires a relatively high torque motor to drive both the hands of theclock and the pendulum.

This invention is concerned with a battery-powered simulated pendulumclock wherein the pendulum does not serve a timekeeping function, andhas as its general object the provision of a unique driving movement forthe pendulum which may be operated with low battery power.

Some of the prior art electronic battery-operated clocks have utilizedrelatively small pendulums which are intimately connected with thetimekeeping movement of the clock for providing a mechanical oscillatorto accurately synchronize the frequency of an electronic oscillator.However, such pendulums commonly have the drive force applied to thependulum some distance from the fulcrum of the pendulum so that such aclock cannot take on the appearance of an oldfashioned pendulum clock.Accordingly, it is also an object of this invention to provide a uniquedriving mechanism for a pendulum which may be located very close to thefulcrum of the pendulum. With this arrangement, the fulcrumof thependulum and the electromagnetic drive for the pendulum may be coveredby a clock casing so that a person viewing the pendulum clock mayreadily observe the hands of the clock and the pendulum without seeingthe electromagnetic drive mechanism.

SUMMARY OF THE INVENTION In accordance with one of the aspects of thisinvention, an electronic movement powered by direct current is providedfor driving the hands or other time display elements of a clock, and apendulum including an elongated arm and a bob is mounted below theelectronic timekeeping movement. A unique electromagnetic drivemechanism is positioned close to the fulcrum of the pendulum for drivingthe pendulum. The electromagnetic drive includes a highly permeablefield and coil for driving a permanent magnet which is attached to anarm of the pendulum.

BRIEF DESCRIPTION OF THE DRAWING Other objects and attendant advantagesof the invention will be apparent from the following description takenin connection with the accompanying drawing in which:

FIG. I is a front elevational view of my improved pendulum clock partlybroken away to show details of construction;

FIG. 2 is a front elevational view of the pendulum movement and thependulum of the clock shown in FIG. 11;

FIG. 3 is a perspective view of a portion of the pendulum and theelecromagnetic movement for driving the pendulum of the pendulum clockshown in FIG. 1;

FIG. 4 shows an electronic circuit for delivering driving pulses to thependulum for moving the pendulum;

FIG. 5 is an enlarged fragmentary front elevational view of the upperand lower arms of the pendulum; and

FIG. 6 is an enlarged fragmentary side elevational view of the upper andlower arms of the pendulum similar to FIG. 5 showing the lower arm ofthe pendulum being connected to the upper arm of the pendulum.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing andfirst particularly to FIG. I, there is shown a pendulum clock whichincludes my unique pendulum movement construction. In the embodimentillustrated, the clock includes an or namental casing 10 of a type whichis capable of being hung from a wall. A conventional hour hand 12, amin-' ute hand 14, and Roman numerals are provided for indicating thehours and minutes.

The hands of the clock may be driven by any conventional timingmechanism 16, and as shown in FIG. 2 an electronic battery-poweredmovement is utilized for this purpose. The battery-powered movementincludes a casing 18 which may be conveniently formed from plastic orother suitable material. A battery 20 is positioned in an upper portionof the casing and an electric motor 22, a mechanical oscillator 24, andan electronic oscillator circuit 26 is positioned in the lower portionof the casing along with drive gearing 28 for the hands of the clock. Itcan be appreciated that the gearing from the motor 22 is connected to acenter stack of concentric shafts 30 and 32 which extend through a frontwall of the timing mechanism casing and the front casing of the clockfor driving the hour and minute hands 12 and I4, respectively.

The specific electronic battery-operated clock movement illustrated doesnot form a part of my invention and is described and shown in greaterdetail in a prior patent of C. M. Jones U.S. Pat. No. 3,454,856, issuedJuly 8, 1969, and assigned to the same assignee as the instantinvention. In accordance with my invention, a unique separate movementis provided for driving the pendulum.

With particular reference to FIG. 1, it can be appreciated that theusual electronic battery-operated timekeeping movement 16 for drivingthe hands of a clock is not too large, and yet as shown by the dottedlines it occupies a considerable amount of space behind the front faceof the clock. As shown, it extends roughly from the lower portion ofRoman numeral I to the upper portion of numeral VII. My electronicpendulum movement 34 is so small that it may be positioned within acasing 36 which does not extend below the outer circumference of theclock casing 10. In this manner, all of the driving mechanism for thependulum 38 may be position so that it is not seen. Thus, a personviewing the pendulum clock may readily observe the hands of the clockand what appears to be a swinging pendulum with a relatively longpendulum arm 40 and a large decorative pendulum bob 42.

Since the pendulum movement 34 which is powered by direct current isseparate and distinct from the timekeeping mechanism 22, 24 and 26 fordriving the hands of the clock, it can be conveniently housed in theseparate plastic casing 36. As shown, the electrical connections fromthe battery 20 to the separate pendulum movement 34 may be convenientlymade by a pair of electrical wires 48 and 50 which may extend through anaperture 82 which is formed in a top wall of the casing 36.

The pendulum movement casing 36 may be readily attached to theconventional battery-operated clock timing mechanism casing 16 by meansof a sheet metal plate 50 which may be conveniently secured to themechanism casing by a nut 52 and a threaded collar 53 which are alsorequired for assembling the timekeeping movement casing 16 to the clockcasing 10. As illustrated, the sheet metal plate 50 extends downwardlyfrom the collar 53, and the pendulum movement casing 36 may be readilyattached to the plate 50 by any suitable connection means.

The pendulum 40 is constructed .so that a variety of differentornamental pendulums may be operated and driven by my unique pendulummovement 34. The construction details of the pendulum 40 and the generalarrangement of the pendulum 40, the pendulum movement 34, and thetime-keeping movement 16 in a clock do not form a part of this inventionand are described and illustrated in greater detail in a co-pendingapplication of Chester B. Marble (6D-4319), Ser. No. 211,343, assignedto the same assignee as the instant invention. 7

As described in more detail in the aforementioned application, thependulum 40 is constructed in two parts, a very short upper portion 58and a removable lower portion 56. The short upper portion includes aflexible spring fulcrum 60, a drive arm 66, and a bracket portion 74which is provided for supporting a removable lower pendulum arm 56. Theflexible leaf spring fulcrum 60 has its upper end clamped between twoL-shaped brackets 62 and 63 which may be riveted or otherwise secured tothe sheet metal plate 50. The upper drive arm 66 functions as a mountingbracket for supporting a permanent magnet 64 for driving the pendulum.

In accordance with my invention, the permanent magnet 64 for driving thependulum 40 is arranged to be driven by a highly permeable corestructure 101 and coils 102 and 104 so that the relatively largependulum may be readily driven by the magnetic forces produced by thecore and coils although the excursions of the pendulum arm 58 and themagnet 64 in the area where they are being driven may be as small as 0.1to 0.2 inch, and as with most pendulums the swinging frequency could beapproximately one cycle per second.

In accordance with my invention, the magnet 64 is constructed so that itprovides a very high flux density, and it is magnetically coupled to thehighly permeable magnet core structure 101 and its push-pull coils 102and 104. The coil 102 is formed with many turns of wire, and in theembodiment illustrated approximately 5,000 turns are utilized forproviding an adequate field for moving the magnet 64 and the pendulum40. With particular reference to FIG. 3, it can be seen that the gapbetween the two pole pieces of my highly permeable iron core structure101 can be small so that the rate of flux change is large.

With particular reference to FIG. 4, the coils 102 and 104 are providedfor triggering operation of the two transistors 106 and 108. In order toobtain the greatest amount of rate of flux change (voltage) as themagnet 64 on the pendulum swings to and fro the iron utilized in thefield laminations 101 is highly permeable. As illustrated in FIGS. 3 and4, the coil 104 is wound on the same highly permeable magnet corestructure 101 as the 102, and in the embodiment illustrated, the 10,000turn coil 104 operating with my highly permeable magnetic corelaminations 101 may obtain an induced voltage of the order of 0.3 voltsas the magnet moves through its excursion of from 0.1 to 0.2 inch. Thus,in the preferred embodiment illustrated in FIG. 4, the coils 102 and 104alternately feed strong control signals to the input of a two silicontransistor circuit.

My improved circuit illustrated in FIG. 4 is essentially a push-pullswitching oscillator circuit which causes the transistors to alternatelyconduct by signals generated by the swinging magnet 64 on the upperpendulum arm. The circuit contains relatively few components forachieving its unique switching function of alternately providingsubstantial flow to the coils 102 and 104 at just the right times tokeep the pendulum oscillating. The principal components of the circuitare transistors 106 and 108 which are used with intercoupling andfeedback from the coils 102 and 104 resulting in a well performingoscillator. This circuit is quite efficient because of the push-pullarrangement of the coils 102 and 104, respectively. The coil 104 isconnected to the collector of transistor 106 while the coil 102 isconnected to the collector of transistor 108. The coils are essentiallyin parallel and are connected to a battery 110 of approximately 1.5volts or other suitable source of direct current. A 68K resistor 112 ispositioned between the collector of transistor 106 and the base oftransistor 108 while the collector of transistor 108 is directly coupledto the base of transistor 106 to suitably provide intercoupling betweenthe transistors 106 and 108.

A .1 microfarad capacitor 114 is positioned between the bases oftransistors 106 and 108 and the collector of transistor 108 for thesuppression of high frequency oscillations.

A 3.3K resistor 116 is connected to the emitters of the transistors 106and 108 and the negative terminal of battery 110 for increasing theinput impedance of the transistor input circuits.

With this circuit the transistors 106 and 108 are readily turned on andoff by signals generated by the swinging magnet 64 on the pendulum 40.When the transistor MP8 is off transistor 106 is on and the magnetswings under the force provided by coil 104. Alternately, whentransistor 106 is off transistor W8 is on and the magnet swings underthe force provided by coil W2 thereby keeping the pendulum in motion.

From the foregoing description, it will be appreciated that my uniqueseparate electromagnetic motor may be readily operated as a truependulum with its pleasing swinging motion although the frequency ofoscillation of the electronic transistor oscillator is much higher thanthe pendulum frequency. Moreover, in contrast to the usual pendulum myelectrically driven pendulum is less sensitive to the operating positionof the clock, and it does not require a length adjustment. Moreover,with my highly permeable field and coil assembly the electromagneticdrive for the upper arm of the pendulum is applied so close to thefulcrum portion of the pendulum that the portion of the lower pendulumarm and the pendulum bob may be visible substantially in their entiretyand may be made quite long while the relatively small drive mechanismmay be conveniently shielded from an observer by the clock casing.

What I claim is:

l. A pendulum clock powered by direct current comprising:

a. a direct current operated timekeeping movement;

b. a time display mechanism operatively connected to said timekeepingmovement for displaying time;

c. a pendulum including an elongated arm and a pendulum bob attached tosaid elongated arm and positioned below said timekeeping movement, saidpendulum being separate from said timekeeping movement and having noelectrical, mechanical or synchronizing driving connection with saidtime keeping movement;

d. a direct current electromagnetic movement for driving said pendulumpositioned below said timekeeping movement, said electromagneticmovement including an electric circuit for providing driving impulses;

e. said electromagnetic movement for driving said pendulum including apermanent magnet connected to said elongated arm and arranged formovement with the pendulum; and

f. a highly permeable magnetic core having a coil wound thereonconnected to said electric circuit for providing electromagneticimpulses to move said magnet to drive said pendulum.

2. A low power direct current operated pendulum clock as defined inclaim ll wherein said pendulum bob is attached to said elongated arm,said elongated arm and bob are positioned below said timekeepingmovement, and said electric circuit is a transistor oscillator circuitwhich is connected to said coil for energizing said coil.

3. A pendulum clock as defined in claim 2 wherein said coil is providedfor driving said permanent magnet in one direction and a second coil isprovided for driving said permanent magnet in an opposite direction andboth of said coils being wound on the highly permeable magnetic core,said second coil being energized by said transistor oscillator circuit.

4!. For use with a clock, a simulated pendulum movement having noelectrical, mechanical or synchronizing driving connection with atimekeeping movement of the clock comprising:

a. a pendulum including an elongated arm and a pendulum bob attached tothe elongated arm;

b. a fulcrum for said pendulum;

c. a permanent magnet for driving and controlling movement of saidpendulum connected to said pendulum arm close to said fulcrum;

d. a highly permeable magnet core structure positioned close to saidpermanent magnet;

e. a first coil having a first end and a second end wound around saidhighly permeable magnet core for driving said permanent magnet in onedirection;

f. a second coil having a first end and a second end for driving saidpermanent magnet in a direction opposite to said one direction;

g. an oscillator including a first transistor, a second transistor and asource of direct current; and

h. means including an electric connection from the second end of thefirst coil to the base of the first transistor to transmit inducedpulses from the first coil to the base of said first transistor toenergize the second coil to move the magnet and the pendulum in saidopposite direction, one end of the second coil being connected to thecollector of said first transistor and the other end of the second coilbeing connected to a first end of the first coil and said currentsource, the second end of said first coil being connected to thecollector of said second transistor, the collector of said firsttransistor being connected to the base of said second transistor tocontrol conduction of said second transistor to energize the first coilto move the magnet and the pendulum in said one direction, the emittersof said first and second transistors being connected to said currentsource.

5. A low power direct current operated pendulum clock comprising:

a. a timekeeping movement;

b. a time display mechanism operatively connected to said timekeepingmovement to display time;

c. a pendulum including a fulcrum portion, an elongated arm, and apendulum bob attached to said elongated arm, said elongated arm and bobbeing positioned below and separated from said timekeeping movement,said pendulum being separate from said timekeeping movement and havingno electrical, mechanical or synchronizing driving connection with saidtimekeeping movement;

d. an electromagnetic movement separate from said timekeeping movementfor driving said pendulum, said separate electromagnetic pendulummovement being positioned below said timekeeping movement, saidelectromagnetic movement including an electric circuit for providingdriving impulses to a permanent magnet which is connected to andarranged for movement with the pendulum;

e. said electromagnetic pendulum movement being positioned with respectto the elongated arm of the pendulum for applying a drive force to thependulum very close to the fulcrum portion of the pendulum, saidelongated pendulum arm and bob extending a substantial distance belowsaid electromagnetic pendulum movement; and

f. a highly permeable magnetic core having a coil wound thereonconnected to said electric circuit for providing electromagneticimpulses to move said magnet to drive said pendulum.

1. A pendulum clock powered by direct current comprising: a. a directcurrent operated timekeeping movement; b. a time display mechanismoperatively connected to said timekeeping movement for displaying time;c. a pendulum including an elongated arm and a pendulum bob attached tosaid elongated arm and positioned below said timekeeping movement, saidpendulum being separate from said timekeeping movement and having noelectrical, mechanical or synchronizing driving connection with saidtimekeeping movement; d. a direct current electromagnetic movement fordriving said pendulum positioned below said timekeeping movement, saidelectromagnetic movement including an electric circuit for providingdriving impulses; e. said electromagnetic movement for driving saidpendulum including a permanent magnet connected to said elongated armand arranged for movement with the pendulum; and f. a highly permeablemagnetic core having a coil wound thereon connected to said electriccircuit for providing electromagnetic impulses to move said magnet todrive said pendulum.
 2. A low power direct current operated pendulumclock as defined in claim 1 wherein said pendulum bob is attached tosaid elongated arm, said elongated arm and bob are positioned below saidtimekeeping movement, and said electric circuit is a transistoroscillator circuit which is connected to said coil for energizing saidcoil.
 3. A pendulum clock as defined in claim 2 wherein said coil isprovided for driving said permanent magnet in one direction and a secondcoil is provided for driving said permanent magnet in an oppositedirection and both of said coils being wound on the highly permeablemagnetic core, said second coil being energized by said transistoroscillator circuit.
 4. For use with a clock, a simulated pendulummovement having no electrical, mechanical or synchronizing drivingconnection with a timekeeping movement of the clock comprising: a. apendulum including an elongated arm and a pendulum bob attached to theelongated arm; b. a fulcrum for said pendulum; c. a permanent magnet fordriving and controlling movement of said pendulum connected to saidpendulum arm close to said fulcrum; d. a highly permeable magnet corestructure positioned close to said permanent magnet; e. a first coilhaving a first end and a second end wound around said highly permeablemagnet core for driving said permanent magnet in one direction; f. asecond coil having a first end and a second end for driving saidpermanent magnet in a direction opposite to said one direction; g. anoscillator including a first transistor, a second transistor and asource of direct current; and h. means including an electric connectionfrom the second end of the first coil to the base of the firsttransistor to transmit induced pulses from the first coil to the base ofsaid first transistor to energize the second coil to move the magnet andthe pendulum in said opposite direction, one end of the second coilbeing connected to the collector of said first transistor and the otherend of the second coil being connected to a first end of the first coiland said current source, the second end of said first coil beingconnected to the collector of said second transistor, the collector ofsaid first transistor being connected to the base of said secondtransistor to control conduction of said second transistor to energizethe first coil to move the magnet and the pendulum in said onedirection, the emitters of said first and second transistors beingconnected to said current source.
 5. A low power direct current operatedpendulum clock comprising: a. a timekeeping movement; b. a time displaymechanism operatively connected to said timekeeping movement to displaytime; c. a pendulum including a fulcrum portion, an elongated arm, and apendulum bob attached to said elongated arm, said elongated arm and bobbeing positioned below and separated from said timekeeping movement,said pendulum being separate from said timekeeping movement and havingno electrical, mechanical or synchronizing driving connection with saidtimekeeping movement; d. an electromagnetic movement separate from saidtimekeeping movement for driving said pendulum, said separateelectromagnetic pendulum movement being positioneD below saidtimekeeping movement, said electromagnetic movement including anelectric circuit for providing driving impulses to a permanent magnetwhich is connected to and arranged for movement with the pendulum; e.said electromagnetic pendulum movement being positioned with respect tothe elongated arm of the pendulum for applying a drive force to thependulum very close to the fulcrum portion of the pendulum, saidelongated pendulum arm and bob extending a substantial distance belowsaid electromagnetic pendulum movement; and f. a highly permeablemagnetic core having a coil wound thereon connected to said electriccircuit for providing electromagnetic impulses to move said magnet todrive said pendulum.